The present invention relates to fungicidal compositions, methods of making the compositions and methods of applying such compositions to control fungal diseases of plants. Phosphorus containing compounds with fungicidal properties and fertilizer capabilities have already been proposed as disclosed in the prior patents detailed herein. None of these patents however, include as an active ingredient, a complex organic composition derived from natural organic materials such as leonardite, lignite, peat, shale, sediments and soil. Such organic compositions are believed to enhance the effectiveness of the phosphorus containing compounds in controlling fungal diseases.
Standard fertilizers generally comprise blends of one or more nitrogen containing compounds (e.g. nitrate or ammonium salts), a phosphorus containing compound (e.g. phosphate), and potassium. Such fertilizers are generally not used for their fungicidal effect. These fertilizers have been combined with liquid plant growth modification compositions of the type described in U.S. Pat. No. 4,698,090 issued to Marihart and/or with liquid plant growth compositions of the type described in U.S. Pat. No. 4,786,307 issued to Marihart. The U.S. Pat. No. 4,698,090 discloses a process for extraction of humic acids by reacting organic chelating agents with leonardite ore, and U.S. Pat. No. 4,786,307 discloses methods of preparing chelated micronutrient compositions containing fulvic acid substantially free of humic acid and extracted from leonardite ore with a chelant. These extracts from leonardite ore are complex compositions containing thousands of interactive compounds, the beneficial effects and properties of which are not fully understood.
Nutritional functions of humic substances are described in U.S. Pat. No. 6,080,220 issued to Sequi, et al. That patent discloses that the nutritional functions of humic substances are both direct, when the nutritive elements are released in the course of slow mineralization of humic substances themselves, and indirect, when their ability to complex and chelate the metals that are found in the liquid phase allow for plant uptake of the nutrients. In nature the indirect nutritional function is considered the more important one for making available different nutritional metals, such as iron, calcium, and magnesium. Humic substances tend to chelate the metals present in the soil solution, thus preventing the precipitation of the metals in the forms of oxides, hydroxides or carbonates, which then become unusable because they are in insoluble forms that cannot be absorbed by the root hairs of plants. Chelation by the humic substances makes the metals available for nutritional purposes.
U.S. Pat. No. 5,830,255 issued to Lovatt and U.S. Pat. No. 6,113,665 issued to Lovatt, disclose concentrated water dilution fertilizers comprising buffered compositions of a phosphorus containing acid or salt thereof which, when diluted with water, have a foliage acceptable pH for phosphorus uptake as a fertilizer.
Compositions for control of fungus are known including, for example, the fungicidal compositions containing phosphorous acid disclosed in U.S. Pat. No. 4,075,324 issued to Thizy and the commercial ALIETTE® WDG composition containing aluminum tris (O-ethyl phosphonate) as active ingredient from Aventis Crop Science which is foliarly applied for control of Downy Mildew in lettuce crops. Another example of a composition for the control of fungus is the use of phosphate and phosphonate disclosed in U.S. Pat. No. 6,338,860 issued to Taylor and the commercial PHOS-MIGHT composition from Foliar Nutrients, Incorporated for control of Phytophthora infection in plants. More effective fungicidal compositions are desired, particularly those, which are also capable of stimulating and enhancing plant growth, and have little effect on the environment.
Historically, application of fungicidal materials has been predominantly limited to foliar applications. Since the mode of action of most of these materials has been of a contact nature, direct contact of the fungicide with the disease organism has been one the limiting factors impacting the efficacy of many fungicides. Applications of the materials directly to the plant foliage have been the most widespread methods of delivery. This direct application method is inherently expensive as it requires foliar application apparatus and labor to apply these materials. Further reductions in efficacy are attributed to “washing-off” by rain or sprinklers which removes the fungicide from its intended location of placement. More recently newer fungicide chemistries have allowed for application of these fungicides to the soil. Applications of phosphorus fungicide materials directly to the soil are subject to chemical “tie-up” and have been limited in their effectiveness under soil conditions.